In a traditional optical transceiver board, there is a matched set of optical transmitter (TX) and receiver (RX) entities, or ports. While the traditional approach of having a receiver matched with a transmitter is still possible, it is inefficient for certain PON scenarios.
The traditional approach of managing the TX and RX ports would use four RX circuits which would then match Media Access Control (MAC) interface electronics. The Media Access Control (MAC) data communication protocol sub-layer is the part of the seven-layer OSI model data link layer (layer 2). It provides addressing and channel access control mechanisms that make it possible for several terminals or network nodes to communicate within a multipoint network. The MACs would then be managed for the respective portion of the total upstream traffic from the Optical Network Terminal (ONT) on the PON. A passive optical network (PON) is a system that brings optical fiber cabling and signals all or most of the way to the end user. A PON consists of an Optical Line Termination (OLT) at the communication company's office and a number of Optical Network Units (ONUs) near end users. A PON typically consists of an OLT, which resides in a Central Office (CO). The OLT typically services a number of ONUs that are usually connected in a star arrangement using optical splitters, which reside at a premise of a user. PONs are designed on the premise of time-sharing of resources. This traditional solution would require four receivers plus potentially four MAC electrical interfaces.
Referring to FIG. 1, a traditional system 100 comprises an optical transceiver board 102 with a matched set of optical transmitter (TX) and receiver (RX) ports 106. Each TX/RX port is coupled to a MAC interface 104. A wavelength-division multiplexer (WDM) 108 is coupled to each of the ports 106 to multiplex the optical carrier signal, and to a combiner 110, which is a passive device that combines the optical power carried by many input fibers into a single output fiber. The combiner 110 is coupled to an external PON 112. As previously mentioned, this type of a system is inefficient.
Therefore, what is needed is an ability to overcome these problems and limitations to allow the RX and TX ports to be managed more efficiently.